PDE10 inhibitors and related compositions and methods

ABSTRACT

Compounds that inhibit PDE10 are disclosed that have utility in the treatment of a variety of conditions, including (but not limited to) psychotic, anxiety, movement disorders and/or neurological disorders such as Parkinson&#39;s disease, Huntington&#39;s disease, Alzheimer&#39;s disease, encephalitis, phobias, epilepsy, aphasia, Bell&#39;s palsy, cerebral palsy, sleep disorders, pain, Tourette syndrome, schizophrenia, delusional disorders, drug-induced psychosis and panic and obsessive-compulsive disorders. The compounds have the general structure: 
                         
wherein m, n, p, x, R, R 1 , R 2 , R 3 , R 4 , R 5 , A and B, are defined herein, including pharmaceutically acceptable salts, stereoisomers, solvates or prodrugs thereof. Also disclosed are compositions containing a compound of this invention in combination with a pharmaceutically acceptable carrier, as well as methods relating to the use thereof for inhibiting PDE10 in a warm-blooded animal in need of the same.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/944,270 filed Nov. 21, 2007, which claims the benefit under35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/866,745filed Nov. 21, 2006 and U.S. Provisional Patent Application No.60/896,386 filed Mar. 22, 2007. The foregoing applications areincorporated herein by reference in their entireties.

BACKGROUND

1. Technical Field

This invention relates generally to compounds having activity as PDE10inhibitors, and to compositions containing the same, as well as tomethods of treating various disorders by administration of suchcompounds to a warm-blooded animal in need thereof.

2. Description of the Related Art

Cyclic nucleotide phosphodiesterases (PDEs) are represented by a largesuperfamily of enzymes. PDEs are known to possess a modulararchitecture, with a conserved catalytic domain proximal to the carboxylterminus, and regulatory domains or motifs often near the aminoterminus. The PDE superfamily currently includes more than twentydifferent genes subgrouped into eleven PDE families (Lugnier, C.,“Cyclic nucleotide phosphodiesterase (PDE) superfamily: a new target forthe development of specific therapeutic agents.” Pharmacol Ther. 2006March; 109(3):366-98).

A recently described PDE, PDE10, was reported simultaneously by threeindependent groups (Fujishige et al., “Cloning and characterization of anovel human phosphodiesterase that hydrolyzes both cAMP and cGMP(PDE10A),” J Biol Chem 1999, 274:18438-18445; Loughney et al.,“Isolation and characterization of PDE10A, a novel human 3′,5′-cyclicnucleotide phosphodiesterase,” Gene 1999, 234:109-117; Soderling et al.,“Isolation and characterization of a dual-substrate phosphodiesterasegene family: PDE10A,” Proc Natl Acad Sci USA 1999, 96:7071-7076). PDE10has the capacity to hydrolyze both cAMP and cGMP; however, the K_(m) forcAMP is approximately 0.05 μM, whereas the K_(M) for cGMP is 3 μM. Inaddition, the V_(max) for cAMP hydrolysis is fivefold lower than forcGMP. Because of these kinetics, cGMP hydrolysis by PDE10 is potentlyinhibited by cAMP in vitro, suggesting that PDE10 may function as acAMP-inhibited cGMP phosphodiesterase in vivo. Unlike PDE8 or PDE9,PDE10 is inhibited by IBMX with an IC₅₀ (50% inhibitory concentration)of 2.6 μM. (See Soderling and Beavo, “Regulation of cAMP and cGMPsignaling: new phosphodiesterases and new functions,” Current Opinion inCell Biology, 2000, 12:174-179.)

PDE10 contains two amino-terminal domains that are similar to thecGMP-binding domains of PDE2, PDE5 and PDE6, which are domains conservedacross a wide variety of proteins. Because of the wide conservation ofthis domain, it is now referred to as the GAF domain (for the GAFproteins: cGMP binding phosphodiesterases; the cynobacterial Anabaenaadenylyl cyclase; and the Escherichia coli transcriptional regulatorfhlA). Although in PDE2, PDE5 and PDE6 the GAF domains bind cGMP, thisis probably not the primary function of this domain in all cases (e.g.,E. coli are not thought to synthesize cGMP). Interestingly, in vitrobinding studies of PDE10 indicate the dissociation constant (K_(d)) forcGMP binding is well above 9 μM. As in vivo concentrations of cGMP arenot thought to reach such high levels in most cells, it seems likelythat either the affinity of PDE10 for cGMP is increased by regulation,or that the primary function of the GAF domain in PDE10 may be forsomething other than cGMP binding.

Inhibitors of the PDE family of enzymes have widely been sought for abroad indication of therapeutic uses. Reported therapeutic uses of PDEinhibitors include allergies, obtrusive lung disease, hypertension,renal carcinoma, angina, congestive heart failure, depression anderectile dysfunction (WO 01/41807 A2). Other inhibitors of PDE have beendisclosed for treatment of ischemic heart conditions (U.S. Pat. No.5,693,652). More specifically, inhibitors of PDE10 have been disclosedfor treatment of certain neurological and psychiatric disordersincluding, Parkinson's disease, Huntington's disease, schizophrenia,delusional disorders, drug-induced psychosis and panic andobsessive-compulsive disorders (U.S. Patent Application No.2003/0032579). PDE10 has been shown to be present at high levels inneurons in areas of the brain that are closely associated with manyneurological and psychiatric disorders. By inhibiting PDE10 activity,levels of cAMP and cGMP are increased within neurons, and the ability ofthese neurons to function properly is thereby improved. Thus, inhibitionof PDE10 is believed to be useful in the treatment of a wide variety ofconditions or disorders that would benefit from increasing levels ofcAMP and cGMP within neurons, including those neurological, psychotic,anxiety and/or movement disorders mentioned above.

While advances have been made with regard to inhibition of PDE10, thereremains a need in the field for inhibitors of PDE10, as well as the needto treat various conditions and/or disorders that would benefit from thesame.

BRIEF SUMMARY

In brief, this invention is generally directed to compounds that haveactivity as PDE10 inhibitors, as well as to methods for theirpreparation and use, and to pharmaceutical compositions containing thesame. More specifically, the compounds of this invention have thefollowing general structure (I):

including pharmaceutically acceptable salts, stereoisomers, solvates andprodrugs thereof, wherein A, B, m, n, p, x, R, R¹, R², R³, R⁴ and R⁵ areas defined below.

The compounds of this invention have utility over a wide range oftherapeutic applications, and may be used to treat a wide variety ofconditions or disorders that would benefit from increasing levels ofcAMP and cGMP, especially within neurons, including (but not limited to)psychotic disorders, anxiety disorders, movement disorders and/orneurological disorders such as Parkinson's disease, Huntington'sdisease, Alzheimer's disease, encephalitis, phobias, epilepsy, aphasia,Bell's palsy, cerebral palsy, sleep disorders, pain, Tourette'ssyndrome, schizophrenia, delusional disorders, bipolar disorders,post-traumatic stress disorders, drug-induced psychosis, panicdisorders, obsessive-compulsive disorders, attention-deficit disorders,disruptive behavior disorders, autism, depression, dementia, cognitivedisorders, epilepsy, insomnias and multiple sclerosis.

The methods of this invention include administering an effective amountof a compound of structure (I), typically in the form of apharmaceutical composition, to a mammal in need thereof, including ahuman. Thus, in still a further embodiment, pharmaceutical compositionsare disclosed containing one or more compounds of structure (I) incombination with a pharmaceutically acceptable carrier or diluent.

These and other aspects of the invention will be apparent upon referenceto the following detailed description. To this end, various referencesare set forth herein which describe in more detail certain backgroundinformation, procedures, compounds and/or compositions, and are eachhereby incorporated by reference in their entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates that compound 5-1 (Table 3) increases prepulseinhibition (PPI) similar to olanzapine. C57BL/6 male mice were injectedintraperitoneally (i.p.) with either compound or vehicle as described inExample 9. FIG. 1A shows that olanzapine (3 mg/kg) significantlydecreases the startle response (left panel) and increases PPI at 3different prepulse levels (right panel) compared to vehicle control (*p<0.05, n=8 per group, student's t-test). FIG. 1B shows that compound5-1 (50 mg/kg) does not affect the startle response (left panel) butsignificantly increases PPI at 3 different prepulse levels (right panel)compared to vehicle control (* p<0.05, ** p<0.01, n=24 per group,student's t-test).

FIG. 2 illustrates that compound 5-1 (Table 3) reduces PCP-inducedhyperactivity similar to olanzapine and haloperidol as described inExample 10. FIG. 2A shows that both olanzapine (0.2 mg/kg) andhaloperidol (0.2 mg/kg) significantly reduce the hyperactivity (leftpanel) and stereotypy (right panel) induced by PCP as seen in thevehicle+PCP control (p<0.001, n=8 per group, repeated measures ANOVA).FIG. 2B shows that compound 5-1 (50 mg/kg) completely abolishes thehyperactivity (left panel) and stereotypy (right panel) induced by PCPas seen in the vehicle+PCP control (p<0.001, n=8 per group, repeatedmeasures ANOVA).

FIG. 3 illustrates that compound 5-1 (Table 3) reducesamphetamine-induced hyperactivity similar to olanzapine, as described inExample 11. FIG. 3A shows that olanzapine (0.2 mg/kg) partially butsignificantly reduce the hyperactivity (left panel) and stereotypy(right panel) induced by amphetamine (“amph”) as seen in thevehicle+amph control (p<0.05, n=8 per group, repeated measures ANOVA).FIG. 3 B shows that compound 5-1 (50 mg/kg) also partially butsignificantly reduce the hyperactivity (left panel) and stereotypy(right panel) induced by amphetamine as seen in the vehicle+amph control(p<0.01, n=8 per group, repeated measures ANOVA).

FIG. 4 illustrates that compound 5-1 (Table 3) reduces ConditionedAvoidance Response (CAR) similar to haloperidol and olanzapine, asdescribed in Example 12. FIG. 4A shows that haloperidol (0.15 mg/kg)significantly reduces the number of avoidance response (*** p<0.001, n=6per group, paired t-test). FIG. 4B shows that olanzapine (0.45 mg/kg)significantly reduces the number of avoidance response (** p<0.01, n=6per group, paired t-test). FIG. 4C shows that compound 5-1 (30 mg/kg)significantly reduces the number of avoidance response (*** p<0.001, n=6per group, paired t-test). In all these cases, the numbers of escaperesponse increase correspondingly and the total numbers of transitionsbetween the two chambers do not change (data not shown), indicating aspecific reduction of CAR that is not due to compromised motor function.

FIG. 5 illustrates that compound 5-110 (Table 3) exhibits antipsychoticproperties in two behavioral tests, as described in Example 13. FIG. 5Ashows that compound 5-110 (10 mg/kg) significantly reduces the number ofavoidance response in the CAR test (** p<0.01, n=6 per group, pairedt-test). FIG. 5B shows that compound 5-110 (30 mg/kg) significantlyreduces the hyperactivity (left panel) and stereotypy (right panel)induced by PCP (5 mg/kg) (p<0.001, n=8 per group, repeated measuresANOVA).

FIG. 6 illustrates that compound 5-103 (Table 3) reduces ConditionedAvoidance Response (CAR), as described in Example 14. Compound 5-103 (10mg/kg) significantly reduces the number of avoidance response (**p<0.01, n=6 per group, paired t-test).

FIG. 7 illustrates that PCP (5 mg/kg) disrupts novel object recognition,and that compound 5-184 (10 mg/kg) is able to restore performance inthis test. In contrast, olanzapine (1 mg/kg) is unable to restore thisPCP-disrupted behavior (**p<0.01 when compared to PCP-treated group, n=8per group, ANOVA with post-hoc Bonferroni test).

DETAILED DESCRIPTION

As mentioned above, the present invention is directed generally tocompounds useful as PDE10 inhibitors, as well as to methods for theirpreparation and use, and to pharmaceutical compositions containing thesame. The PDE10 inhibitors of this invention have the followingstructure (I):

or a pharmaceutically acceptable salt, stereoisomer, solvate or prodrugthereof,

-   -   wherein:        -   m, n and p are individually 0 or 1;        -   x is 1, 2 or 3;        -   A is an optionally substituted heterocycle;        -   B is —O—, —NR⁶— or —S(O)_(z)— where z is 0, 1 or 2;        -   R is hydrogen or oxo;        -   R¹ is absent or represents 1, 2 or 3 substituents that are            the same or different and independently halogen, C₁₋₆alkyl,            —CHF₂, —CF₃, —CH₂NH₂, —CH₂NH(C₁₋₆alkyl) or            —CH₂N(C₁₋₆alkyl)₂;        -   R² is at each occurrence the same or different and            independently, hydrogen, C₁₋₆alkyl, —C(═O)(C₁₋₆alkyl),            benzyl, —CH₂CONH₂, —CHF₂, —CF₃, or any two R² groups, or any            R² group and R¹ group, may be taken together to form a            C₁₋₆alkanediyl; and        -   R³, R⁴, R⁵ and R⁶ are the same or different and            independently hydrogen or C₁₋₆alkyl.

As used herein, the above terms have the following meaning:

“C₁₋₆alkyl” means a straight chain or branched, noncyclic or cyclic,unsaturated or saturated aliphatic hydrocarbon containing from 1 to 6carbon atoms. Representative saturated straight chain alkyls includemethyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, and the like; whilesaturated branched alkyls include isopropyl, sec-butyl, isobutyl,tert-butyl, isopentyl, and the like. Representative saturated cyclicalkyls include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and thelike; while unsaturated cyclic alkyls include cyclopentenyl andcyclohexenyl, and the like. Unsaturated alkyls contain at least onedouble or triple bond between adjacent carbon atoms (referred to as an“alkenyl” or “alkynyl”, respectively). Representative straight chain andbranched alkenyls include ethylenyl, propylenyl, 1-butenyl, 2-butenyl,isobutylenyl, 1-pentenyl, 2-pentenyl, 3-methyl-1-butenyl,2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, and the like; whilerepresentative straight chain and branched alkynyls include acetylenyl,propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl,3-methyl-1-butynyl, and the like.

“C₁₋₆alkanediyl” means a divalent C₁₋₆alkyl from which two hydrogenatoms are taken from the same carbon atom or from different carbonatoms, such as —CH₂—, —CH₂CH₂—, —CH═CH—, —CH═C(CH₃)—, —CH₂CH₂CH₂—,—CH₂CH═CH—, —CH(CH₃)CH₂CH₂—, —CH₂C(CH₃)₂CH₂—, and the like.

“Heterocycle” means a 4- to 7-membered monocyclic, or 7- to 10-memberedbicyclic, heterocyclic ring which is either saturated, unsaturated oraromatic, and which contains from 1 to 4 heteroatoms independentlyselected from nitrogen, oxygen and sulfur, and wherein the nitrogen andsulfur heteroatoms may be optionally oxidized, and the nitrogenheteroatom may be optionally quaternized, including bicyclic rings inwhich any of the above heterocycles are fused to a benzene ring. Theheterocycle may be attached via any heteroatom or carbon atom. Anaromatic heterocycle is referred to herein as a “heteroaryl”, andincludes (but is not limited to) furyl, benzofuranyl, thiophenyl,benzothiophenyl, pyrrolyl, indolyl, isoindolyl, azaindolyl, pyridyl,quinolinyl, isoquinolinyl, oxazolyl, isooxazolyl, benzoxazolyl,pyrazolyl, imidazolyl, benzimidazolyl, thiazolyl, benzothiazolyl,isothiazolyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl,cinnolinyl, phthalazinyl, oxadiazolyl, thiadiazolyl, benzisoxazolyl,triazolyl, tetrazolyl, indazolyl and quinazolinyl. In addition to theheteroaryls listed above, heterocycles also include morpholinyl,pyrrolidinonyl, pyrrolidinyl, piperidinyl, piperazinyl, and the like.

The term “optionally substituted” as used in the context of anoptionally substituted heterocycle (as well heteroaryl) means that atleast one hydrogen atom is replaced with a substituent. In the case ofan oxo substituent (“═O”) two hydrogen atoms are replaced. Whensubstituted, one or more of the above groups are substituted.“substituents” within the context of this invention include halogen,hydroxy, oxo, cyano, nitro, amino, alkylamino, dialkylamino, alkyl,alkoxy, alkylthio, haloalkyl, aryl, arylalkyl, heteroaryl,heteroarylalkyl, heterocycle and heterocyclealkyl, as well as—NR_(a)R_(b), —NR_(a)C(═O)R_(b), —NR_(a)C(═O)NR_(a)NR_(b),—NR_(a)C(═O)OR_(b), —NR_(a)SO₂R_(b), —C(═O)R_(a), —C(═O)OR_(a),—C(═O)NR_(a)R_(b), —OC(═O)NR_(a)R_(b), —OR_(a), —SR_(a), —SOR_(a),—S(═O)₂R_(a), —OS(═O)₂R_(a) and —S(═O)₂OR_(a). In addition, the abovesubstituents may be further substituted with one or more of the abovesubstituents, such that the substituent is a substituted alkyl,substituted aryl, substituted arylalkyl, substituted heterocycle orsubstituted heterocyclealkyl. R_(a) and R_(b) in this context may be thesame or different and independently hydrogen, alkyl, haloalkyl,substituted alkyl, aryl, substituted aryl, arylalkyl, substitutedarylalkyl, heterocycle, substituted heterocycle, heterocyclealkyl orsubstituted heterocyclealkyl.

In one embodiment, both m and n are 0 and p is 1, and the compounds havethe following structure (II) or a pharmaceutically acceptable salt,stereoisomer, solvate or prodrug thereof:

In another embodiment, m, n and p are 1, and the compounds have thefollowing structure (III) or a pharmaceutically acceptable salt,stereoisomer, solvate or prodrug thereof:

In another embodiment, m is 0 and n and p are both 1, and the compoundshave the following structure (IV) or a pharmaceutically acceptable salt,stereoisomer, solvate or prodrug thereof:

In another embodiment, both m and p are 1 and n is 0, and the compoundshave the following structure (V) or a pharmaceutically acceptable salt,stereoisomer, solvate or prodrug thereof:

In another embodiment, each of m, n and p are 0, and the compounds havethe following structure (VI) or a pharmaceutically acceptable salt,stereoisomer, solvate or prodrug thereof:

In more specific embodiments of structure (II), R³, R⁴ and R⁵ arehydrogen.

In other more specific embodiments of structure (II), R² is methyl ordifluoromethyl.

In other more specific embodiments of structure (II), R¹ is absent and xis 3 with the R² groups at the 3, 4 and 5 positions, as represented bystructure (IIa):

In yet further specific embodiments of structure (II), A is1H-indol-3-yl or 2H-benzo[b][1,4]thiazin-3(4H)-one-2-yl.

In more specific embodiments of structure (IV), B is —S—, —O— or —NR⁶—,respectively, and compounds have the following structures (IVa), (IVb)and (IVc):

In more specific embodiments of structures (IVa), (IVb) and (IVc), R³,R⁴, R⁵ and R⁶ are hydrogen.

In other more specific embodiments of structures (IVa), (IVb) and (IVc),R² is hydrogen, methyl, ethyl, difluoromethyl, 2-propenyl,2-methylpropyl, C₁alkanediyl, —CH₂CONH₂. In yet further specificembodiments, R² is methyl.

In other more specific embodiments of structures (IVa), (IVb) and (IVc),R¹ is absent or halogen, x is 2 with the R² groups located at the 3 and4 positions, or x is 3 with the R² groups located at the 3, 4 and 5positions, as represented by structures (IVd) and (IVe), respectively:

In other more specific embodiments of structures (IVa), (IVb) and (IVc),R¹ is 2 substituents that are the same or different and independentlyhalogen, such as fluorine, as represented by structure (IVf):

In other more specific embodiments of structures (IVa), (IVb) and (IVc),A is

x is 3 and the —OR² groups are located at the 3, 4 and 5 positions, R¹is absent, R² is at each occurrence the same or different andindependently hydrogen, C₁₋₆alkyl, —C(═O)(C₁₋₆alkyl), benzyl, —CH₂CONH₂,—CHF₂ or —CF₃, and R³, R⁴ and R⁵ are hydrogen. In yet further specificembodiments, R² is at each occurrence the same or different andindependently, C₁₋₆alkyl or —CHF₂ or —CF₃.

In other more specific embodiments of structures (IVa), (IVb) and (IVc),A is

x is 2 or 3 and two of the —OR² groups are located at the 3 and 4positions, R¹ is absent, R² is at each occurrence the same or differentand independently C₁₋₆alkyl, —CHF₂ or —CF₃, R³, R⁴ and R⁵ are hydrogen,and R⁷ is —O(C₁₋₆alkyl).

In yet further specific embodiments of structure (IVa), A is anoptionally substituted quinolin-4-yl as represented by structure (IVg)where a is 1, 2, 3 or 4, b is 1 or 2 and R⁷ and R⁸ are the same ordifferent and independently hydrogen, halogen, C₁₋₆alkyl, —O(C₁₋₆alkyl),C₁₋₆haloalkyl or nitro.

In further specific embodiments of structure (IVg), x is 1 with theproviso that R¹ is not hydrogen or methyl.

In other further specific embodiments of structure (IVg), x is 2 or 3with the proviso that R¹ is not hydrogen.

In other further specific embodiments of structure (IVg), x is at leastone and R¹ and R² are taken together to form —CH═C(CH₃)—.

In other further specific embodiments of structure (IVg), x is 1, 2 or3, a is 1, b is 0, R¹ is absent or represents 1, 2, or 3 substituentsthat are the same or different and independently halogen, C₁₋₆alkyl,—CHF₂, —CF₃, —CH₂NH₂, —CH₂NH(C₁₋₆alkyl) or —CH₂N(C₁₋₆alkyl)₂, R² is ateach occurrence the same or different and independently hydrogen,C₁₋₆alkyl, —C(═O)(C₁₋₆alkyl), benzyl, —CH₂CONH₂, —CHF₂ or —CF₃, R³, R⁴and R⁵ are hydrogen, and R⁷ is halogen or C₁₋₆haloalkyl. In yet furtherspecific embodiments, R² is at each occurrence the same or different andindependently C₁₋₆alkyl, —CHF₂ or —CF₃. In yet further specificembodiments, R¹ is absent or represents 1, 2, or 3 substituents that arethe same or different and independently halogen, C₁₋₆alkyl, —CHF₂ or—CF₃.

In other further specific embodiments of structure (IVg), a is 1, 2, 3or 4, b is 1 or 2, x is 1, 2 or 3 with the proviso that when x is 1, R¹is not a single methyl substituent, R¹ represents 1 or 2 substitutentsindependently halogen, C₁₋₆alkyl, —CHF₂ or —CF₃, R² is at eachoccurrence the same or different and independently, hydrogen, C₁₋₆alkyl,benzyl, —CH₂CONH₂, —CHF₂, —CF₃, or any two R groups may be takentogether to form a C₁₋₆alkanediyl, R³, R⁴ and R⁵ are the same ordifferent and independently hydrogen or C₁₋₆alkyl, and R⁷ and R⁸ are thesame or different and independently hydrogen, halogen, C₁₋₆alkyl,—O(C₁₋₆alkyl), C₁₋₆haloalkyl or nitro. In yet further specificembodiments, R³, R⁴ and R⁵ are hydrogen. In yet further specificembodiments, R⁷ is hydrogen, R⁸ is —CH₃, a is 1, b is 1 and the compoundhas the following structure:

In other further specific embodiments of structure (IVa), A is2-methylquinolyn-4-yl, quinolin-4-yl, 2-methyl-6-nitroquinolin-4-yl,6-bromoquinolin-4-yl, 8-methoxy-5-methylquinolin-4-yl,6,7-dimethoxy-2-methylquniolin-4-yl, 8-methoxyquinolin-4-yl,7-(trifluoromethyl)quinolin-4-yl,2-methyl-8-(trifluoromethyl)quinolin-4-yl or 6-methoxyquinolin-4-yl.

In yet further specific embodiments of structure (IVa), A is anoptionally substituted 1-benzyl-1H-benzo[d]imidazol-2-yl as representedby structure (IVh) where c is 1, 2, 3, 4 or 5 and R⁹ is hydrogen orhalogen.

In other further specific embodiments of structure (IVh), c is 1, 2, 3,4 or 5, x is 1, 2 or 3, R¹ is absent or represents 1 or 2 halogens, R²is at each occurrence the same or different and independently, hydrogen,C₁₋₆alkyl, benzyl, —CH₂CONH₂, —CHF₂, or any two R² groups may be takentogether to form a C₁₋₆alkanediyl, R³, R⁴ and R⁵ are the same ordifferent and independently hydrogen or C₁₋₆alkyl, and R⁹ is at eachoccurrence the same or different and independently, hydrogen or halogen.In yet further specific embodiments, R³, R⁴ and R⁵ are hydrogen. In yetfurther specific embodiments, c is 1 and R⁹ is hydrogen or chlorine.

In other further specific embodiments of structure (IVh), A is1-benzyl-1H-benzo[d]imidazol-2-yl,1-(2-chlorobenzyl)-1H-benzo[d]imidazol-2-yl or1-(4-chlorobenzyl)-1H-benzo[d]imidazol-2-yl.

In more specific embodiments of structures (I) through (VI) above, anytwo two R² groups, or any R² group and R¹ group, may be taken togetherto form a C₁₋₆alkanediyl. For example, when two R² groups are takentogether to form a C₁₋₆alkanediyl (such as —CH₂—) representativecompounds have the following structure (1-1), and when an R² group andR¹ group are taken together to form a C₁₋₆alkanediyl (such as—CH═C(CH₃)—) representative compounds have the following structure(1-2):

The compounds of the present invention may be prepared by known organicsynthesis techniques, including the methods described in more detail inthe Examples, or in some instances may be obtained from commerciallyavailable sources. In general, the compounds of structure (I) above maybe made by the following reaction schemes, wherein all substituents areas defined above unless indicated otherwise.

Compounds of formula (1) can be obtained commercially or synthesizedthrough standard literature methods. Compounds of formula (1) can bereacted with a variety of benzaldehyde derivatives of formula (2) inalcoholic solvents, such as ethanol, and in the presence of a catalyticamount of acid, such as acetic acid, and under reflux to providecompounds of structure (II).

Compounds of formula (3) can be prepared by standard methods orpurchased commercially and reacted with compounds of formula (4) whereX═Br, Cl and the like, and Y=Me, Et and the like in an appropriatealcoholic solvent such as ethanol and in the presence of a base, such aspotassium carbonate and heated to reflux to provide compounds of formula(5). Compounds of formula (5) in ethanol can then be reacted with ahydrazine compound, such as (6), at reflux to provide compounds offormula (7). Compounds of formula (7) can then be reacted with a varietyof aryl carbonyl derivatives of formula (2) in alcoholic solvents, suchas ethanol, and in the presence of a catalytic amount of acid, such asacetic acid, and under reflux to provide compounds of structure (III).

Compounds of formula (8) can be purchased commercially or prepared viastandard methods. As shown in Scheme 3, compounds of formula (8) can bereacted with compounds of formula (4) where X═Br, Cl and the like andY=Me, Et and the like in an appropriate alcoholic solvent, such asethanol, and in the presence of a base, such as potassium carbonate, andheated to reflux to provide compounds of formula (9). Compounds offormula (9) in ethanol can then be reacted with a hydrazine compound,such as (6), at reflux to provide compounds of formula (10). Compoundsof formula (10) can then be reacted with a variety of aryl carbonylderivatives of formula (2) in alcoholic solvents, such as ethanol, andin the presence of a catalytic amount of acid, such as acetic acid, andunder reflux to provide compounds of structure (IV).

Compounds of formula (11) where Y=Me, Et, and the like can be obtainedcommercially or prepared via standard methods. Compounds of formula (11)in ethanol can be reacted with a hydrazine compound such as (6) toobtain compounds of formula (12). Compounds of formula (12) can then bereacted with a variety of benzaldehyde derivatives, such as (2), inalcoholic solvents, such as ethanol, and in the presence of a catalyticamount of acid, such as acetic acid, and under reflux to providecompounds of structure (V).

Compounds of formula (13) where Y=methyl (Me), ethyl (Et), etc. can beobtained commercially or prepared via standard methods. Compounds offormula (13) in ethanol can be reacted with a hydrazine compound, suchas (6), to obtain compounds of formula (14). Compounds of formula (14)can then be reacted with a variety of benzaldehyde derivatives, such as(2), in alcoholic solvents, such as ethanol, and in the presence of acatalytic amount of acid, such as acetic acid, and under reflux toprovide compounds of structure (VI).

The compounds of the present invention may generally be utilized as thefree acid or free base. Alternatively, the compounds of this inventionmay be used in the form of acid or base addition salts. Acid additionsalts of the free amino compounds of the present invention may beprepared by methods well known in the art, and may be formed fromorganic and inorganic acids. Suitable organic acids include maleic,fumaric, benzoic, ascorbic, succinic, methanesulfonic, acetic,trifluoroacetic, oxalic, propionic, tartaric, salicylic, citric,gluconic, lactic, mandelic, cinnamic, aspartic, stearic, palmitic,glycolic, glutamic, and benzenesulfonic acids. Suitable inorganic acidsinclude hydrochloric, hydrobromic, sulfuric, phosphoric, and nitricacids. Base addition salts included those salts that form with thecarboxylate anion and include salts formed with organic and inorganiccations such as those chosen from the alkali and alkaline earth metals(for example, lithium, sodium, potassium, magnesium, barium andcalcium), as well as the ammonium ion and substituted derivativesthereof (for example, dibenzylammonium, benzylammonium,2-hydroxyethylammonium, and the like). Thus, the term “pharmaceuticallyacceptable salt” of structures (I) through (VI) is intended to encompassany and all acceptable salt forms.

In addition, prodrugs are also included within the context of thisinvention. Prodrugs are any covalently bonded carriers that release acompound of structures (I) through (VI) in vivo when such prodrug isadministered to a patient. Prodrugs are generally prepared by modifyingfunctional groups in a way such that the modification is cleaved, eitherby routine manipulation or in vivo, yielding the parent compound.Prodrugs include, for example, compounds of this invention whereinhydroxy, amine or sulfhydryl groups are bonded to any group that, whenadministered to a patient, cleaves to form the hydroxy, amine orsulfhydryl groups. Thus, representative examples of prodrugs include(but are not limited to) acetate, formate and benzoate derivatives ofalcohol and amine functional groups of the compounds of structures (I)through (VI). Further, in the case of a carboxylic acid (—COOH), estersmay be employed, such as methyl esters, ethyl esters, and the like.

With regard to stereoisomers, the compounds of structures (I) through(VI) may have chiral centers and may occur as racemates, racemicmixtures and as individual enantiomers or diastereomers. All suchisomeric forms are included within the present invention, includingmixtures thereof. Furthermore, some of the crystalline forms of thecompounds of structures (I) through (VI) may exist as polymorphs, whichare included in the present invention. In addition, some of thecompounds of structures (I) through (VI) may also form solvates withwater or other organic solvents. Such solvates are similarly includedwithin the scope of this invention.

In another embodiment of the invention, pharmaceutical compositionscontaining one or more compounds of structures (I) through (VI) aredisclosed. For the purposes of administration, the compounds of thepresent invention may be formulated as pharmaceutical compositions.Pharmaceutical compositions of the present invention comprise one ormore compounds of the present invention and a pharmaceuticallyacceptable carrier and/or diluent. The PDE10 inhibitor is present in thecomposition in an amount which is effective to treat a particulardisorder—that is, in an amount sufficient to achieve desired PDE10inhibition, and preferably with acceptable toxicity to the warm-bloodedanimal. Typically, the pharmaceutical compositions of the presentinvention may include a PDE10 inhibitor in an amount from 0.1 mg to 250mg per dosage depending upon the route of administration, and moretypically from 1 mg to 60 mg. Appropriate concentrations and dosages canbe readily determined by one skilled in the art.

In general terms, a typical daily dosage might range from about 1 μg/kgto 100 mg/kg, preferably 0.01-100 mg/kg, more preferably 0.1-70 mg/kg,depending on the type and severity of the disease whether, for example,by one or more separate administrations. For repeated administrationsover several days or longer, depending on the condition, the treatmentis sustained until a desired suppression of disease symptoms occurs.However, other dosage regimens may be useful. The progress of thistherapy can be monitored by standard techniques and assays. Thespecification for the dosage unit forms of the invention are dictated byand directly dependent on the unique characteristics of the activecompound and the particular therapeutic effect to be achieved, and thelimitations inherent in the art of compounding such an active compoundfor the treatment of individuals.

Pharmaceutically acceptable carrier and/or diluents are familiar tothose skilled in the art. For compositions formulated as liquidsolutions, acceptable carriers and/or diluents include saline andsterile water, and may optionally include antioxidants, buffers,bacteriostats and other common additives. The compositions can also beformulated as pills, capsules, granules, or tablets which contain, inaddition to a PDE10 inhibitor, diluents, dispersing and surface activeagents, binders, and lubricants. One skilled in this art may furtherformulate the PDE10 inhibitor in an appropriate manner, and inaccordance with accepted practices, such as those disclosed inRemington's Pharmaceutical Sciences, Gennaro, Ed., Mack Publishing Co.,Easton, Pa. 1990.

In another embodiment, the present invention provides a method fortreating diseases such as (but not limited to) psychotic disorders,anxiety disorders, movement disorders and/or neurological disorders suchas Parkinson's disease, Huntington's disease, Alzheimer's disease,encephalitis, phobias, epilepsy, aphasia, Bell's palsy, cerebral palsy,sleep disorders, pain, Tourette's syndrome, schizophrenia, delusionaldisorders, bipolar disorders, post-traumatic stress disorders,drug-induced psychosis, panic disorders, obsessive-compulsive disorders,attention-deficit disorders, disruptive behavior disorders, autism,depression, dementia, cognitive disorders, epilepsy, insomnias andmultiple sclerosis as discussed above. Such methods includeadministering of a compound of the present invention to a warm-bloodedanimal in an amount sufficient to treat the condition. In this context,“treat” includes prophylactic administration. Such methods includesystemic administration of a PDE10 inhibitor of this invention,preferably in the form of a pharmaceutical composition as discussedabove. As used herein, systemic administration includes oral andparenteral methods of administration, including subcutaneous,intramuscular, intracranial, intraorbital, ophthalmic, intraventricular,intracapsular, intraarticular, intraspinal, intracisternal,intraperitoneal, intranasal, aerosol, intravenous, intrademmal,inhalational, transdermal, transmucosal, and rectal administration.

For oral administration, suitable pharmaceutical compositions of PDE10inhibitors include powders, granules, pills, tablets, and capsules aswell as liquids, syrups, suspensions, and emulsions. These compositionsmay also include flavorants, preservatives, suspending, thickening andemulsifying agents, and other pharmaceutically acceptable additives andexcipients. For parenteral administration, the compounds of the presentinvention can be prepared in aqueous injection solutions which maycontain, in addition to the PDE10 inhibitor, buffers, antioxidants,bacteriostats, and other additives and excipients commonly employed insuch solutions. Compositions of the present invention may be carried ina delivery system to provide for sustained release or enhanced uptake oractivity of the therapeutic compound, such as a liposomal or hydrogelsystem for injection, a microparticle, nanopartical or micelle systemfor oral or parenteral delivery, or a staged capsule system for oraldelivery.

In a further advantage of the present invention, compounds of structures(I) through (VI) are expected to avoid or reduce metabolic side effectsassociated with conventional antipsychotics, in particular the incidenceof therapeutically induced obesity. For example, chronic use ofolanzapine (Zyprexa®), the most widely prescribed medication to treatschizophrenia, and related atypical antipsychotics is associated withsignificant metabolic side effects including obesity and associatedconditions such as diabetes.

In animals, subchronic treatment with olanzapine stimulates food intakeand increases body weight, consistent with human situations.Furthermore, olanzapine acutely lowers blood leptin levels. Leptin is asatiety hormone produced from adipose tissues, and decrease of leptinlevel stimulates appetite. It is theorized that olanzapine couldstimulate food intake at least partly by reducing leptin levels. Acuteadministration of olanzapine also changes the animal's response inglucose and insulin levels in glucose tolerance tests, which may also bedirectly linked to olanzapine's effect in food intake and body weightgain. Examination of the acute effect of PDE10 inhibitors of the presentinvention on metabolism, such as leptin, insulin and glucose changesduring a metabolic challenge in standard animal models, as well as thechronic effect of PDE10 inhibitors of the present invention in foodintake, body weight and energy homeostasis, in comparison witholanzapine should provide evidence to the pharmaceutical advantage ofPDE10 inhibitors as antipsychotics in terms of less side-effectconcerns.

The compositions of the present invention may be administered incombination with one or more additional therapeutic agents, incombination or by concurrent or sequential administration. Suitableadditional agents (i.e., adjuvants) may include typical antipsychoticsthat block dopamine-D₂ receptors and serotonin 5HT₂ receptors, e.g.,haloperidol, fluphenazine, chlorpromazine, and atypical antipsychotics,e.g., clozapine, olanzapine, risperidone, quetiapine, ziprasidone.

Compounds of this invention may be assayed to determine their IC₅₀values by a modification of the two-step method of Thompson and Appleman(Biochemistry 10; 311-316; 1971). In short, cAMP is spiked with (³H)cAMPand incubated with PDE10 and various concentrations of a compound ofstructure (I). After the appropriate incubation time, the reaction isterminated by heating. The mixture is then subjected to treatment withsnake venom phosphatase. The phosphatase hydrolyzes any AMP in themixture, but leaves unreacted cAMP intact. Thus, by separating cAMP fromthe mixture and determining its concentration (by radiography), thepercent of inhibition can be determined. IC₅₀ values can be calculatedby performing the experiment at several concentrations using standardgraphical means. A detailed description of the actual technique used forIC₅₀ assays are shown in Example 8. To this end, PDE10 inhibitors of theinvention have an IC₅₀ of 100 μM or less, generally less than 10 μM, andtypically less than 1 μM.

The following examples are provided for purposes of illustration, notlimitation.

EXAMPLES Example 1(E)-2-(3-OXO-3,4-DIHYDRO-2H-BENZO[B][1,4]THIAZIN-2-YL)-N′-(3,4,5-TRIMETHOXYBENZYLIDENE)ACETOHYDRAZIDE

In a round-bottom glass flask equipped with a magnetic stir bar(3-Oxo-3,4-dihydro-2H-benzo[1,4]thiazin-2-yl)-acetic acid hydrazide (1eq. 0.063 mmol; 15 mg) was dissolved in ethanol (3 mL) at roomtemperature. To this well stirred solution, acetic acid (˜3 drops) and3,4,5-trimethoxy-benzaldehyde solution (0.063 mmol; 12.4 mg dissolved in0.5 mL of ethanol) were added, and the reaction mixture was stirred foranother 5 hours at ambient temperature and monitored by TLC (typicallywith 1,2-dichloroethane-ethanol 5:1). The mixture was then concentratedunder vacuum using a rotary evaporator. The crude product was dilutedwith hexanes and triturated. The precipitated solid product wastransferred to a glass fiber funnel, the supernatant was removed byvacuum filtration and the solid was washed thoroughly with n-hexanetwice to yield: 16 mg (61%) of 1-1.

Example 2(E)-2-(1H-INDOL-3-YL)-N′-(3,4,5-TRIMETHOXYBENZYLIDENE)ACETOHYDRAZIDE

In a round-bottom glass flask equipped with a magnetic stir bar(1H-indol-3-yl)-acetic acid hydrazide (1 eq. 0.793 mmol; 150 mg) wasdissolved in ethanol (10 mL) at room temperature. To this well stirredsolution, acetic acid (˜3 mL) and the 3,4,5-trimethoxy-benzaldehydesolution (1 eq. 0.793 mmol; 155.5 mg dissolved in 5 mL of ethanol) wereadded dropwise. The reaction mixture was stirred at room temperatureuntil the reaction was complete (approximately 2 hours) as determined byTLC (typically with 1,2-dichloroethane-ethanol 5:1). The mixture wasthen concentrated under reduced pressure. The crude product was dilutedwith hexanes and triturated. The precipitated solid product wastransferred to a glass fiber funnel, the supernatant was removed byvacuum filtration and the solid was washed thoroughly with n-hexanetwice to yield 104 mg (36%) of 2-1.

Referring to Table 1 below, the listed derivatives of structure (II),where R³, R⁴ and R⁵ are hydrogen, were synthesized according to theprocedures outlined in Examples 1 and 2.

TABLE 1 (II)

No. MW A R¹ x R² 1-1  415.47

H 3 3-CH₃ 4-CH₃ 5-CH₃ 2-1  367.40

H 3 3-CH₃ 4-CH₃ 5-CH₃ 2-2  403.38

H 3 3-CH₃ 4-CHF₂ 5-CH₃ 2-3  367.40

H 3 2-CH₃ 4-CH₃ 5-CH₃ 2-4  415.47

H 3 2-CH₃ 4-CH₃ 5-CH₃ 2-5  355.37

2-F 2 4-CH₃ 5-CH₃ 2-6  410.43

H 3 3-CH₃ 4-CH₂CONH₂ 5-CH₃ 2-7  451.45

H 3 3-CH₃ 4-CHF₂ 5-CH₃ 2-8 458.49

H 3 3-CH₃ 4-CH₂CONH₂ 5-CH₃ 2-9 351.41

H 2 3-CH₃ 4-CH₃ 2-10 338.37

H 2 3-CH₃ 4-CH₃ 2-11 332.38

H 2 3-CH₃ 2-COCH₃ 2-12 339.35

H 2 3-CH₃ 4-CH₃ 2-13 333.43

H 2 3-CH₂CH₃ 4-CH₂CH₃ 2-14 488.54

H 2 3-CH₃ 4-CH₃ 2-15 369.40

H 2 3-CH₂-4 2-16 371.41

H 2 3-H 4-CH₃ 2-17 385.44

H 2 3-CH₂CH₃ 4-H 2-18 489.57

H 2 3-benzyl 4-benzyl 2-19 321.34

H 2 3-CH₂-4 2-20 367.40

H 3 2-CH₃ 3-CH₃ 4-CH₃ 2-21 491.57

H 3 3-CH₃ 4-benzyl 5-CH₃ 2-22 443.50

H 3 3-CH₃ 4-benzyl 5-CH₃ 2-23 415.47

H 3 2-CH₃ 3-CH₃ 4-CH₃ 2-24 537.64

H 2 3-benzyl 4-benzyl

As used in Table 1 above, as well as in the tables that follow, thenumbers preceding (and following in the case of alkanediyls) the R¹ andR² substituents refer to the substituent's position on the aromatic ringas shown below.

Example 3(E)-N-(2-(2-(4-HYDROXY-3-METHOXYBENZYLIDENE)HYDRAZINYL)-2-OXOETHYL)ISONICOTINAMIDE

Referring to Table 2, the above derivative of structure (III), where R¹,R³, R⁴ and R⁵ are hydrogen, can be synthesized by Reaction Scheme 2 fromcorresponding intermediate 5.

TABLE 2 (III)

No. MW A B R R⁶ x R² 3-1 328.32

NR⁶ ═O H 2 3-CH₃ 4-H

Example 4(E)-2-(1-BENZYL-1H-BENZO[D]IMIDAZOL-2-YLTHIO)—N′-(4-ETHOXY-3-METHOXYBENZYLIDENE)ACETOHYDRAZIDEStep 4A Preparation of ethyl 2-(1H-benzo[d]imidazol-2-ylthio)acetate 4a

To a stirred solution of 1H-benzo[d]imidazole-2(3H)-thione (20.0 g, 0.13mol, 1.0 eq.) in anhydrous ethanol (500 mL) at room temperature, wasadded potassium carbonate (9.25 g, 0.07 mol, 0.5 eq.) and ethylbromoacetate (26.7 g, 0.16 mmol, 1.2 eq.). The reaction was heated toreflux and stirred at that temperature for 6 hours. The solvent wasremoved in vacuo and water (200 mL) was added. The aqueous phase wasextracted with dichloromethane (3×100 mL), and the combined organicextracts were washed with water (200 mL) and brine (200 mL). The organicphase was dried over magnesium sulfate and concentrated in vacuo to givea colorless oil which solidified on standing. Purification by flashchromatography (CHCl₃→10% MeOH:90% CHCl₃) gave 4a as a white solid (11.7g, 37%).

Step 4B Preparation of ethyl2-(1-benzyl-1H-benzo[d]imidazol-2-ylthio)acetate 4b

To a stirred solution of ethyl 2-(1H-benzo[d]imidazol-2-ylthio)acetate4a (11.2 g, 47.6 mmol, 1.0 eq.) in 10:1 diethyl ether:dimethylformamide(450 mL) at 0° C., was added 60% sodium hydride in mineral oil (2.09 g,52.3 mmol, 1.1 eq.), and the reaction was stirred at 0° C. for 20minutes. Benzyl bromide (9.78 g, 57.1 mmol, 1.2 eq.) was added at 0° C.,and the reaction was stirred with warming to room temperature for 16hours. The reaction mixture was quenched with methanol (100 mL) andconcentrated in vacuo. The residue was taken into hot chloroform (400mL) and filtered. The filtrate was washed with water (200 mL), 1M HCl(200 mL) and brine (200 mL). The organic layer was dried over magnesiumsulfate and concentrated in vacuo. Purification by flash chromatography(10% EtOAc:90% petroleum ether) gave 4b as a pale-yellow solid (4.82 g,30%).

Step 4C Preparation of2-(1-benzyl-1H-benzo[d]imidazol-2-ylthio)acetohydrazide 4c

To a stirred solution of ethyl2-(1-benzyl-1H-benzo[d]imidazol-2-ylthio)acetate 4b (200 mg, 0.61 mmol,1.0 eq.) in ethanol (5 mL), was added hydrazine monohydrate (61 mg, 1.23mmol, 2.0 eq.), and the reaction mixture was heated to reflux andstirred at that temperature for 16 hours. The reaction mixture wascooled to room temperature and concentrated in vacuo. The mixture wasdissolved in ethyl acetate (20 mL) and washed with water (20 mL) andbrine (20 mL). The organic layer was dried over magnesium sulfate andconcentrated in vacuo giving 4c as a pale yellow solid which was usedwithout further purification (200 mg, 100%).

Step 4D Preparation of(E)-2-(1-benzyl-1H-benzo[d]imidazol-2-ylthio)-N′-(4-ethoxy-3-methoxybenzylidene)acetohydrazide4-1

To a stirred solution of2-(1-benzyl-1H-benzo[d]imidazol-2-ylthio)acetohydrazide 4c (200 mg, 0.61mmol, 1.0 eq.) in ethanol (5 mL), was added3-methoxy-4-ethoxybenzaldehyde (110 mg, 0.61 mmol, 1.0 eq.) and aceticacid (3 drops). The mixture was heated to reflux and stirred at thattemperature for 16 hours. The reaction mixture was cooled to roomtemperature, and the precipitate that formed on cooling was filtered andwashed with water (10 mL), ethanol (10 mL) and diethyl ether (10 mL).The solid was dried by high vacuum overnight giving 4-1 as a white solid(196 mg, 67%).

Example 5(E)-N′-(3,4-DIMETHOXYBENZYLIDENE)-2-(2-METHYLQUINOLIN-4-YLTHIO)ACETOHYDRAZIDEHYDROCHLORIDE Step 5A Preparation of 2-methylquinoline-4-thiol 5a

A stirred suspension of 2-methylquinolin-4-ol (5.10 g, 32.0 mmol, 1.0eq.) in tetrahydrofuran (51 mL) was heated to 50° C., and 6.5 g ofLawesson's Reagent (6.5 g, 16.0 mmol, 0.5 eq.) was added in one portion.The reaction was heated to 80° C. and stirred at that temperature for 6hours. The reaction was poured into a hot biphasic solution of ethylacetate (200 mL) and water (200 mL) and was vigorously stirred. Aviscous orange gel precipitated from the solution. The water/ethylacetate solution was decanted into a separating funnel and the organiclayer isolated. The aqueous layer was extracted with ethyl acetate(4×200 ml), and the combined extracts were dried over magnesium sulfate.The solution was filtered and concentrated in vacuo. The resultingorange gel was purified by flash chromatography (50% EtOAc:50% petroleumether→100% EtOAc) to yield 5a as a yellow solid (1.70 g, 30%).

Step 5B Preparation of methyl 2-(2-methylquinolin-4-ylthio)acetate 5b

2-methylquinoline-4-thiol 5a (1.00 g, 5.71 mmol, 1.00 eq.) was dissolvedin dimethylformamide (10 mL) at room temperature. Potassium carbonate(0.87 g, 6.28 mmol, 1.10 eq.) was added and the mixture was stirred for15 minutes. Methyl bromoacetate (921 mg, 6.02 mmol, 1.05 eq.) was addeddropwise to the solution, and the reaction was stirred at roomtemperature for 2.5 hours. Water (20 mL) was added to the reactionmixture, and the aqueous layer was extracted with ethyl acetate (30 mL).The aqueous layer was further extracted with ethyl acetate (3×50 mL),and the combined organic layers were dried over magnesium sulfate,filtered and concentrated in vacuo. The resulting residue was dried onhigh vacuum to yield 5b as a brown solid (1.25 g, 88%).

Step 5C Preparation of 2-(2-methylquinolin-4-ylthio)acetohydrazide 5c

Example 5, Step 5C was performed in an analogous fashion to Example 4,Step 4C.

Step 5D Preparation of(E)-N′-(3,4-dimethoxybenzylidene)-2-(2-methylquinolin-4-ylthio)acetohydrazide5-1

Example 5, Step 5D was performed in an analogous fashion to Example 4,Step 4D.

Step 5E Preparation of(E)-N′-(3,4-dimethoxybenzylidene)-2-(2-methylquinolin-4-ylthio)acetohydrazidehydrochloride 5-1a

2-(2-methylquinolin-4-ylsulfanyl)-aceticacid-(3,4-dimethoxybenzylidene)-hydrazide 5-1 (220 mg, 0.56 mmol, 1.0eq.) in methanol (40 mL) and dimethylsulfoxide (2 mL) was heated to 100°C. for 2 hours until completely dissolved before being allowed to coolto 50° C. 1.25 M methanolic hydrochloric acid (1 eq.) was then added,and the mixture was stirred for 20 min before partially concentrating invacuo. The product was then obtained through filtration and dried togive 5-1a (180 mg, 75%).

Referring to Table 3, the following derivatives of structure (IV),wherein R³ is hydrogen, were synthesized according to the proceduresoutlined in Examples 4 and 5 (in the following table, an R¹ substituentis absent when H is designated).

TABLE 3 (IV)

No. MW A B R¹ p x R² R⁴ R⁵ 4-1  474.58

S H 1 2 3-CH₃ 4-CH₂CH₃ H H 5-1  395.48

S H 1 2 3-CH₃ 4-CH₃ H H 5-2  526.56

S H 1 3 3-CH₃ 4-CHF₂ 5-CH₃ H H 5-3  561.01

S H 1 3 3-CH₃ 4-CHF₂ 5-CH₃ H H 5-4  512.99

S 2-F 1 2 4-CH₃ 5-CH₃ H H 5-5  525.03

S H 1 3 2-CH₃ 4-CH₃ 5-CH₃ H H 5-6  525.03

S H 1 3 3-CH₂CH₃ 4-H H H 5-7  478.55

S 2-F 1 2 4-CH₃ 5-CH₃ H H 5-8  460.56

S H 1 2 3-CH₂CH₃ 4-H H H 5-9  490.58

S H 1 3 2-CH₃ 4-CH₃ 5-CH₃ H H 5-10  533.61

S H 1 3 3-CH₃ 4-CH₂CONH₂ 5-CH₃ H H 5-11  460.56

S H 1 2 2-CH₃ 4-CH₃ H H 5-12  411.48

S H 1 2 3-CH₃ 4-CH₃ H H 5-13  360.44

S H 1 2 3-CH₃ 4-CH₃ H H 5-14  473.55

S H 1 2 3-CH₃ 4-CH₃ H H 5-15  331.39

S H 1 2 3-CH₃ 4-CH₃ H H 5-16  384.46

S H 1 2 3-CH₃ 4-CH₃ H H 5-17  381.45

S H 1 2 3-CH₃ 4-CH₃ H H 5-18  387.48

S H 1 2 2-CH₃ 3-CH₃ H H 5-19  430.53

S H 1 1 4-CH₃ H H 5-20  331.39

S H 1 2 3-H 4-CH₂CH₃ H H 5-21  361.42

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-22  459.53

S H 1 2 3-CH₃ 4-H H H 5-23  432.50

S H 1 2 3-H 4-H H H 5-24  370.43

S H 1 2 3-CH₃ 4-CH₃ H H 5-25  490.58

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-26  460.56

S H 1 2 3-CH₃ 4-CH₃ H H 5-27  495.00

S H 1 2 3-CH₃ 4-CH₃ H H 5-28  474.54

S H 1 2 3-CH₃ 4-CH₃ H H 5-29  409.51

S H 1 2 3-CH₃ 4-CH₃ H H 5-30  387.48

S H 1 2 3-CH₃ 4-CH₃ H H 5-31  474.58

S H 1 2 3-CH₃ 4-CH₃ H H 5-32  371.41

S H 1 2 3-CH₃ 4-CH₃ H H 5-33  495.00

S H 1 2 3-CH₃ 4-CH₃ H H 5-34  423.47

O H 1 3 3-CH₃ 4-CH₂CH₃ 5-CH₃ H H 5-35  446.53

S H 1 2 3-CH₃ 4-H H H 5-35  398.48

S H 1 2 3-CH₃ 4-CH₃ H H 5-37  379.42

O H 1 2 3-CH₃ 4-CH₃ H H 5-38  433.51

O H 1 2 3-CH₃ 4-cyclopentyl H H 5-39  504.61

S H 1 3 3-CH₃ 4-CH₂CH₃ 5-CH₃ H H 5-40  488.61

S H 1 2 3-CH₃ 4-n-propyl H H 5-41  488.61

S H 1 2 3-CH₃CH₃ 4-CH₂CH₃ H H 5-42  463.53

O H 1 3 3-CH₃ 4-cyclopentyl 5-CH₃ H H 5-43  486.59

S H 1 2 3-CH₃ 4-(2)- propenyl H H 5-44  474.58

S H 1 2 3-CH₃ 4-CH₂CH₃ H H 5-45  423.53

S H 1 2 3-CH₃ 4-n-propyl H H 5-46  407.47

O H 1 2 3-CH₃ 4-n-propyl H H 5-47  514.65

S H 1 2 3-cyclopentyl 4-CH₃ H H 5-48  444.51

S H 1 2 3-CH₂-4 H H 5-49  514.65

S H 1 2 3-CH₃ 4-cyclopentyl H H 5-50  518.64

S H 1 3 3-CH₃ 4-n-propyl 5-CH₃ H H 5-51  544.67

S H 1 3 3-CH₃ 4-cyclopentyl 5-CH₃ H H 5-52  612.75

S H 1 2 3-benzyl 4-benzyl H H 5-53  446.53

S H 1 2 3-H 4-CH₃ H H 5-54  490.58

S H 1 3 2-CH₃ 3-CH₃ 4-CH₃ H H 5-55  566.68

S H 1 3 3-CH₃ 4-benzyl 5-CH₃ H H 5-56  647.20

S H 1 2 3-benzyl 4-benzyl H H 5-57  478.96

S H 1 2 3-CH₂-4 H H 5-58  480.97

S H 1 2 3-H 4-CH₃ H H 5-59  525.03

S H 1 3 2-CH₃ 3-CH₃ 4-CH₃ H H 5-60  601.12

S H 1 3 3-CH₃ 4-benzyl 5-CH₃ H H 5-61  456.55

CH2 H 1 2 3-n-propyl 4-CH₃ H H 5-62  486.59

CH2 H 1 2 3-CH2CH3 4-CH₃ H H 5-63  460.56

S H 1 2 3-CH₃ 5-CH₃ H H 5-64  476.55

S H 1 3 3-CH₃ 4-H 5-CH₃ H H 5-65  486.59

S H 1 2 3-cyclopropyl 4-CH₃ H H 5-66  464.97

S 3-Cl 1 1 4-CH₃ H H 5-67  474.58

S H 1 2 3-CH₂CH₃ 4-CH₃ H H 5-68  446.53

S H 1 2 3-H 4-CH₃ H H 5-69  409.51

S H 1 2 3-CH₃ 4-CH₃ H CH₃ 5-70  365.45

S H 1 1 4-CH₃ H H 5-71  474.38

S 3-Br 1 2 4-H 5-CH₂CH₃ H H 5-72  349.39

O H 1 1 2-CH₃ H H 5-73 395.48

S 5-CH₃ 1 2 3-CH₃ 4-H H H 5-74 423.47

O H 1 2 3-CH₃ 4-CH₃ H H 5-75 409.46

S H 1 3 3,4-CH₂- 5-CH₃ H H 5-76  429.93

S 3-Cl 1 2 4-CH₃ 5-CH₃ H H 5-77  474.38

S 3-Br 1 2 4-CH₃ 5-CH₃ H H 5-78  409.44

O H 1 2 3-CH₃ 4-CH₃ H H 5-79  415.46

S 4- CHF₂ 1 1 3-CH₃ H H 5-80  365.39

O H 1 2 3-CH₃ 4-H H H 5-81  363.42

O 3-CH₃ 1 1 4-CH₃ H H 5-82  439.47

O H 1 2 3-CH₃ 4-CH₃ H H 5-83  378.43

NR⁶ (R⁶ = H) H 1 2 3-CH₃ 4-CH₃ H H 5-84  365.39

O H 1 2 3-CH₃ 4-CH₃ H H 5-85  444.29

O 2-Br 1 2 3-H 4-CH₃ H H 5-86  393.40

O H 1 3 3-CH₂-4 5-CH₃ H H 5-87 397.41

O 2-F 1 2 4-CH₃ 5-CH₃ H H 5-88  367.38

O 4-F 1 1 3-CH₃ H H 5-89  399.83

O 3-Cl 1 2 4-H 5-CH₃ H H 5-90  458.32

O 3-Br 1 2 4-H 5-CH₂CH₃ H H 5-91  413.86

O 3-Cl 1 2 4-CH₃ 5-CH₃ H H 5-92  458.32

O 3-Br 1 2 4-CH₃ 5-CH₃ H H 5-93  371.41

O H 1 2 3-CH₃ 4-CH₃ H H 5-94  383.38

O 3-F 1 2 4-H 5-CH₃ H H 5-95  383.83

O 3-Cl 1 1 4-CH₃ H H 5-96  429.42

O H 1 2 3-CH₂CH₃ 4-CHF₂ H H 5-97  415.40

O H 1 2 3-CH₃ 4-CHF₂ H H 5-98  379.42

O 3-CH₃ 1 2 4-H 5-CH₃ H H 5-99  399.40

O 4- CHF₂ 1 1 3-CH₃ H H 5-100 409.44

O H 1 3 2-CH₃ 3-CH₃ 4-CH₃ H H 5-101 409.44

O H 1 3 2-CH₃ 4-CH₃ 5-CH₃ H H 5-102 435.42

S H 1 2 3-CF₃ 4-H H H 5-103 395.48

S H 1 2 3-CH₂CH₃ 4-H H H 5-104 409.51

S H 1 2 3-CH₃ 4-CH₂CH₃ H H 5-105 409.51

S H 1 2 3-CH₂CH₃ 4-CH₃ H H 5-106 447.41

O H 1 2 3-CH₃ 4-CH₃ H H 5-107 424.41

O H 1 2 3-CH₃ 4-CH₃ H H 5-108 365.45

S H 1 1 3-CH₃ H H 5-109 395.48

S H 1 2 3-CH₃ 5-CH₃ H H 5-110 411.48

S H 1 3 3-CH₃ 4-H 5-CH₃ H H 5-111 431.46

S H 1 2 3-CHF₂ 4-CH₃ H H 5-112 437.56

S H 1 2 3- CH₂CH(CH₃)₂ 4-CH₃ H H 5-113 449.45

S H 1 2 3-CF₃ 4-H H H 5-114 425.51

S H 1 2 3-CH₃ 4-CH₃ H H 5-115 486.59

S H 1 2 3-(2)- propenyl 4-CH₃ H H 5-116 488.61

S H 1 2 3-n-propyl 4-CH₃ H H 5-117 400.46

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-118 454.50

S H 1 3 3-CH₃ 4-CH₂CONH₂ 5-CH₃ H H 5-119 447.46

S H 1 3 3-CH₃ 4-CHF₂ 5-CH₃ H H 5-120 487.58

S H 1 3 3-CH₃ 4-benzyl 5-CH₃ H H 5-121 399.44

S 2-F 1 2 4-CH₃ 5-CH₃ H H 5-122 411.48

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-123 411.48

S H 1 3 2-CH₃ 4-CH₃ 5-CH₃ H H 5-124 411.48

S H 1 3 2-CH₃ 3-CH₃ 4-CH₃ H H 5-125 381.45

S H 1 2 3-CH₂CH₃ 4-H H H 5-126 367.43

S H 1 2 3-H 4-CH₃ H H 5-127 365.41

S H 1 2 3-CH₂-4 H H 5-128 533.65

S H 1 2 3-benzyl 4-benzyl H H 5-129 525.03

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-130 490.57

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-131 449.45

S H 1 2 3-CH₃ 4-CH₃ H H 5-132 437.41

S 3-F 1 1 4-CH₃ H H 5-133 437.41

S 4-F 1 1 3-CH₃ H H 5-134 453.87

S 3-Cl 1 1 4-CH₃ H H 5-135 487.42

S 3-CF₃ 1 1 5-CH₃ H H 5-136 449.45

S H 1 2 3-CH₃ 5-CH₃ H H 5-137 425.5

S H 1 2 3-CH₃ 4-CH₃ H H 5-138 413.47

S 3-F 1 1 4-CH₃ H H 5-139 413.47

S 4-F 1 1 3-CH₃ H H 5-140 429.92

S 3-Cl 1 1 4-CH₃ H H 5-141 463.47

S 3-CF₃ 1 1 4-CH₃ H H 5-142 425.5

S H 1 2 3-CH₃ 5-CH₃ H H 5-143 381.45

S H 1 2 3-CH₃ 5-CH₃ H H 5-144 369.41

S 3-F 1 1 4-CH₃ H H 5-145 369.41

S 4-F 1 1 3-CH₃ H H 5-146 385.87

S 3-Cl 1 1 4-CH₃ H H 5-147 419.42

S 3-CF₃ 1 1 4-CH₃ H H 5-148 381.45

S H 1 2 3-CH₃ 5-CH₃ H H 5-149 395.47

S H 1 2 3-CH₃ 4-CH₃ H H 5-150 383.44

S 3-F 1 1 4-CH₃ H H 5-151 383.44

S 4-F 1 1 3-CH₃ H H 5-152 399.89

S 3-Cl 1 1 4-CH₃ H H 5-153 433.45

S 3-CF3 1 1 4-CH₃ H H 5-154 395.47

S H 1 2 3-CH₃ 5-CH₃ H H 5-155 474.37

S H 1 2 3-CH₃ 4-CH₃ H H 5-156 462.34

S 3-F 1 1 4-CH₃ H H 5-157 462.34

S 4-F 1 1 3-CH₃ H H 5-158 478.79

S 3-Cl 1 1 4-CH₃ H H 5-159 512.34

S 3-CF₃ 1 1 5-CH₃ H H 5-160 474.37

S H 1 2 3-CH₃ 5-CH₃ H H 5-161 419.50

S R¹ and R² taken together (see R₂) 1 2

H H 5-162 440.52

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ CH₃ H 5-163 435.55

S H 1 2

H H 5-164 441.50

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-165 439.53

S H 2 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-166 422.48

NR⁶ (R⁶ = CH₃) H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-167 454.54

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-168 361.42

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-169 362.41

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-170 467.44

S H 1 2 3-CHF₂ 4-CHF₂ H H 5-171 387.40

S 3-F 5-F 1 1 4-H H H 5-172 438.54

S 3- CH₂N (CH₃)₂ 1 1 4-H 5-CH₃ H H 5-173 401.43

S 3-F 5-F 1 1 4-CH₃ H H 5-174 385.37

O 2-F 4-F 1 1 3-CH₃ H H 5-175 431.46

S 3-F 5-F 1 1 4-CH₃ H H 5-176 431.46

S 2-F 3-F 1 1 4-CH₃ H H 5-177 401.43

S 2-F 3-F 1 1 4-CH₃ H H 5-178 401.43

S 3-F 5-F 1 1 4-CH₃ H H 5-179 387.40

S 3-F 5-F 1 1 4-CH₃ H H 5-180 381.45

S H 1 2 3-CH₃ 4-CH₃ H H 5-181 455.40

S 2-F 3-F 1 1 4-CH₃ H H 5-182 455.40

S 3-F 5-F 1 1 4-CH₃ H H 5-183 474.37

S 4-Br 1 2 3-CH₃ 5-CH₃ H H 5-184 455.53

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-185 425.5

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-186 459.95

S 3-Cl 1 2 4-CH₃ 5-CH₃ H H 5-187 429.92

S 3-Cl 1 2 4-CH₃ 5-CH₃ H H 5-188 504.4

S 3-Br 1 2 4-CH₃ 5-CH₃ H H 5-189 488.4

S 3-Br 1 2 4-CH₃ 5-CH₂CH₃ H H 5-190 445.92

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-191 413.47

S 3-F 1 2 4-CH₃ 5-CH₃ H H 5-192 474.37

S 2-Br 1 2 4-CH₃ 5-CH₃ H H 5-193 413.47

S 4-F 1 1 3-CH₃ H H 5-194 379.48

S 4-CH₃ 1 1 3-CH₃ H H 5-195 460.34

S 3-Br 1 2 4-CH₃ 5-CH₃ H H 5-196 528.34

S 3-Br 1 2 4-CH₃ 5-CH₃ H H 5-197 411.47

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-198 413.47

S 2-F 1 2 4-CH₃ 5-CH₃ H H 5-199 460.34

S 3-Br 1 2 4-CH₃ 5-CH₃ H H 5-200 429.92

S 2-Cl 1 2 4-CH₃ 5-CH₃ H H 5-201 381.45

S 3-Cl 1 2 4-CH₃ 5-CH₃ H H 5-202 433.45

S 4-CF₃ 1 1 3-CH₃ H H 5-203 483.89

S 3-Cl 1 2 4-CH₃ 5-CH₃ H H 5-204 483.58

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-205 460.34

S 3-Br 1 2 4-CH₃ 5-CH₃ H H 5-206 429.92

S 2-Cl 1 2 3-CH₃ 4-CH₃ H H 5-207 474.37

S 2-Br 1 2 3-CH₃ 4-CH₃ H H 5-208 443.95

S 3-Cl 1 2 4-CH₃ 5-CH₂CH₃ H H 5-209 399.89

S 4-Cl 1 1 3-CH₃ H H 5-210 444.34

S 4-Br 1 1 3-CH₃ H H 5-211 411.47

S H 1 3 3-CH₃ 4-CH₃ 5-CH₃ H H 5-212 409.46

S H 1 3 3-OCH₂O-4 5-CH₃ H H 5-213 423.53

S H 1 2 3-iso-propyl 4-CH₃ H H

Example 6(E)-3-(1-BENZYL-1H-BENZO[D]IMIDAZOL-2-YL)-N′-(3,4-DIMETHOXYBENZYLIDENE)PROPANEHYDRAZIDEStep 6A Preparation of ethyl 3-(1H-benzo[d]imidazol-2-yl)propanoate 6a

To a stirred solution of benzene-1,2-diamine (20.0 g, 0.19 mol, 1.0 eq.)in dioxane (500 mL) at room temperature, was added succinic anhydride(22.2 g, 0.22 mol, 1.2 eq.), and the reaction mixture was heated to 80°C. and stirred at that temperature for 16 hours. The resultingprecipitate was filtered and washed with dioxane (100 mL), water (100mL) and diethyl ether (100 mL) to give a white solid. The solid wassuspended in ethanol (400 mL), and concentrated sulfuric acid (10 mL)was added at room temperature. The reaction mixture was heated to refluxand stirred at that temperature for 20 hours. The reaction was thencooled to room temperature and concentrated in vacuo. Water (100 mL) wasadded, and the mixture was adjusted to pH 7 with 1 M aqueous NaOHsolution. The aqueous layer was extracted into ethyl acetate (3×100 mL),and the combined organic extracts were dried over magnesium sulfate andconcentrated in vacuo to give 6a as a pale-orange oil (15.6 g, 46%).

Step 6B Preparation of ethyl3-(1-benzyl-1H-benzo[d]imidazol-2-yl)propanoate 6b

To a stirred solution of ethyl 3-(1H-benzo[d]imidazol-2-yl)propanoate 6a(2.85 g, 13.1 mmol, 1.0 eq.) in tetrahydrofuran (100 mL) at 0° C., wasadded 60% sodium hydride in mineral oil (784 mg, 19.6 mmol, 1.5 eq.),and the reaction was stirred at 0° C. for 20 minutes. Benzyl bromide(4.47 g, 26.1 mmol, 2.0 eq.) was added at 0° C., and the reaction wasstirred, with warming to room temperature, for 16 hours. The mixture wasconcentrated in vacuo and water (100 mL) was carefully added. Theaqueous layer was extracted with dichloromethane (3×75 mL), and thecombined organic extracts were washed with 1M hydrochloric acid (100 mL)and brine (100 mL). The organic layer was dried over magnesium sulfateand concentrated in vacuo. Purification by flash chromatography (5%MeOH:95% EtOAc) gave 6b as an orange oil (3.32 g, 82%).

Step 6C Preparation of3-(1-benzyl-1H-benzo[d]imidazol-2-yl)propanehydrazide 6c

Step 6C was performed in an analogous fashion to Example 4, Step 4C.

Step 6D Preparation of(E)-3-(1-benzyl-1H-benzo[d]imidazol-2-yl)-N′-(3,4-dimethoxybenzylidene)propanehydrazide6-1

Step 6D was prepared in an analogous fashion to Example 4, Step 4D.

Referring to Table 4, the following derivatives of structure (V),wherein R, R³, R⁴ and R⁵ are hydrogen, were synthesized according to theprocedures outlined in

Example 6

TABLE 4 (V)

No. MW A R¹ x R² 6-1  442.52

H 2 3-CH₃ 4-CH₃ 6-2  382.42

H 2 3-CH₃ 4-CH₃ 5-CH₃ 6-3  387.44

H 2 3-CH₃ 4-H 6-4  320.39

H 2 3-H 4-CH₃ 6-5  336.35

H 2 3-CH₂-4 6-6  338.37

H 2 3-H 4-CH₃ 6-7  352.39

H 2 3-CH₂CH₃ 4-H 6-8  382.42

H 3 2-CH₃ 3-CH₃ 4-CH₃ 6-9  382.42

H 3 2-CH₃ 4-CH₃ 5-CH₃ 6-10 370.38

2-F 2 4-CH₃ 5-CH₃ 6-11 458.52

H 3 3-CH₃ 4-benzyl 5-CH₃ 6-12 456.55

H 2 3-CH₃ 4-CH₂CH₃ 6-13 456.55

H 2 3-CH₂CH₃ 4-CH₃

Example 7

Referring to Table 5, the following derivatives of structure (IV),wherein R⁴ and R⁵ are hydrogen, can be synthesized according to ReactionScheme 5.

TABLE 5 (VI)

No. MW A R¹ x R² 7-1  304.30

H 3 3-CH₃ 4-CH₃ 5-CH₃ 7-2  380.40

H 2 3-CH₃ 4-benzyl 5-CH₃ 7-3  272.26

H 2 3-CH₃ 4-H 7-4  271.28

H 2 3-H 4-CH₃ 7-5  323.35

H 2 3-CH₂CH₃ 4-H 7-6  328.32

H 2 3-CH₃ 4-H 7-7  328.32

H 2 3-H 4-CH₃ 7-8  258.23

H 2 3-CH₂-4 7-9  260.25

H 2 3-H 4-CH₃ 7-10 274.28

H 2 3-CH₂CH₃ 4-H 7-11 304.30

H 3 2-CH₃ 3-CH₃ 4-CH₃ 7-12 304.30

H 3 2-CH₃ 4-CH₃ 5-CH₃ 7-13 292.27

2-F 2 4-CH₃ 5-CH₃ 7-14 340.28

H 3 3-CH₃ 4-CHF₂ 5-CH₃ 7-15 347.33

H 3 3-CH₃ 4-CH₂CONH₂ 5-CH₃

Example 8 Compound Assay

PDE10 Biochemical Assay

The phosphodiesterase (PDE) assay was performed using recombinant humanPDE1A3, 2A3, 3 catalytic region, 4 catalytic region, 5 catalytic region,7A, 8A, 9A2, 10A1 and 11A1 enzymes expressed in a baculoviral systemusing Sf9 cells. PDE activity was measured using a modification of thetwo-step method of Thompson and Appleman described above which wasadapted for 96 well plate format. The effect of the PDE inhibitors wasdetermined by assaying a fixed amount of the enzyme in the presence oftest compound concentrations and a substrate concentration below that ofthe Km, so that Ki equals IC₅₀. The final assay volume was 110 μl withassay buffer (10 mM MgCl₂; 40 mM Tris.HCl; pH 7.4). Reactions wereinitiated with enzyme and incubated with (³H)-substrate and substancefor 20 minutes at 30° C. The reaction was terminated by denaturing theenzyme (heating the reaction to 70° C. for 2 minutes). The reaction wasthen cooled at 4° C. for 10 minutes before the addition of snake venom(Crotalus atrox, 0.2 mg/ml) for 10 minutes at 30° C., thus allowingnon-specific hydrolysis of the tritiated substrate. Separation of theremaining unhydrolysed cyclic nucleotide was achieved by a batch bindingof the mixture to activated Dowex (200 μl) anion exchange resin. Theanion exchange resin bound the charged nucleotides, leaving onlyhydrolysed (3H) substrate in the soluble fraction. The soluble fraction(50 μl) was then added to microscint-20 (200 μl) and counted on a TopCount Plate reader. Radioactivity units were plotted against inhibitorconcentration and IC₅₀ values obtained using Graph Pad Prism software.

Alternatively, phosphodiesterase activity was measured by scintillationproximity assay (SPA) with [³H]-cGMP as substrate. Purified PDE10 wasdiluted and stored in 25 mM Tris-Cl (pH 8.0)/100 mM NaCl/0.05% Tween20/50% glycerol/3 mM DTT. Assays contained (final concentrations): 50 mMTris-Cl (pH 7.5)/8.3 mM MgCl₂/1.7 mM EGTA/0.5 mg/ml BSA/5% DMSO and 2 ngPDE10 in a final volume of 0.1 mL. Inhibition was evaluated at 8concentrations in duplicate. Reactions were initiated by addition ofenzyme and were terminated after 20 minutes at 300 by the addition of 50μl of SPA beads containing Zn⁺⁺. The mixture was shaken, allowed tosettle for 3 hours, and counted in a Wallac plate counter. Results (netcpm) were fitted to a four parameter logistic model using Excel Solver®.

Further, the inhibition of other PDE enzymes by the PDE10 inhibitors wasevaluated under the same conditions described above for PDE10 except theamount of enzyme added was optimized for each PDE. Fractional inhibitionwas evaluated at four concentrations (0.1, 1, 10, and 100 μM). In caseswhere inhibition at the highest concentration was less than 50%, thelower limit value in the logistic model was fixed to 0% activity.

In the above assays, compounds of this invention are PDE10 inhibitorswith an IC₅₀ of 100 μM or less, generally less than 10 μM, and typicallyless than 1 μM. To this end, compounds 1-1, 2-2, 4-1, 5-1, 5-2, 5-3,5-4, 5-5, 5-25, 5-26, 5-27, 5-64, 5-67, 5-73, 5-75, 5-76, 5-77, 5-79,5-91, 5-92, 5-104, 5-105, 5-108, 5-109, 5-110, 5-111, 5-112, 5-114,5-115, 5-118, 5-119, 5-121, 5-122, 5-123, 5-125, 5-129, 5-130, 5-161,5-162, 5-163, 5-183, 5-184, 5-185, 5-186, 5-187, 5-188, 5-189, 5-190,5-191, 5-192, 5-193, 5-194, 5-195, 5-196, 5-197, 5-198, 5-199, 5-200,5-201, 5-202, 5-203, 5-204, 5-205, 5-208, 5-209, 5-210, 5-211, 5-212,and 5-213 were found to have IC₅₀'s of less than or equal to 1 μM.

Examples 9-15 Evaluation of Representative Compounds in BehavioralModels

Schizophrenia has been associated with dysfunctions of dopaminergic,glutamatergic and serotonergic neurotransmission. Psychostimulant drugsin these three classes, dopaminergic agonists (such as amphetamine andapomorphine), glutamatergic antagonists (such as PCP and ketamine), andserotonergic agonists (such as LSD and MDMA), all induce psychotomimeticstates (e.g., hyperactivity and disruption of prepulse inhibition) inanimals that closely resemble schizophrenia symptoms in humans. Knownantipsychotic drugs, including both typical antipsychotics (e.g.,haloperidol) and atypical antipsychotics (e.g., olanzapine), reversesuch psychotomimetic states in animals. Examples 9-14 described belowevaluate representative compounds of the present invention in animalbehavioral models to compare the resulting effect to that of knownantipsychotics. Methods used in the Examples 9-14 are as follows.

Prepulse inhibition (PPI) of the acoustic startle response evaluates thebrain's sensorimotor gating function that is often disrupted inschizophrenic and other psychotic conditions. Psychostimulants such asPCP and amphetamine reduce or disrupt PPI, and many antipsychoticsincrease PPI and/or reverse psychostimulant-induced reduction of PPI. Inaddition, the startle response to the loud noise itself (in the absenceof any prepulse) is a measure of the basic sensorimotor reflex. The testis done using the SR-Lab System (San Diego Instruments, San Diego,Calif.). A test session consists of six trial types under the backgroundnoise of 70 dB. One type uses a 40 msec, 120 dB noise as the startlestimulus. Four types contain acoustic startle stimulus preceded byacoustic prepulses of different intensity: the 20-msec prepulse noise of73, 76, 79, or 82 dB is presented 100 msec before the 120 dB startlestimulus. The last trial type uses the 70 dB background noise with nostartle stimulus to measure baseline reaction. Six blocks of the sixtrial types are presented in pseudorandom order. The startle response isrecorded for 65 ms starting with the onset of the startle stimulus.Measurements used to assess PPI are the maximum startle amplitude andthe percent each of the 4 prepulses inhibits the startle response.

Psychostimulant-induced hyperactivity is measured by injecting animalswith PCP or amphetamine and monitoring the animals' activity levels inthe VersaMax chambers (Accuscan Instruments, Columbus, Ohio) measuring40×40 cm. Locomotor activity is detected by photobeam breaks as theanimal crosses each beam. The animal is placed in the center of thefield and left undisturbed for a period of time (20 min to 2 hr) tomeasure its spontaneous activity in a novel environment. Measurementsused to assess locomotor activity include: horizontal activity, totaldistance traveled, vertical activity (rearing events—animal raises up onhindlimbs), rotation, stereotypy, and distance traveled in the centercompared to total distance traveled (center:total distance ratio).Psychostimulants, including dopamine agonist amphetamine and NMDAantagonist PCP, induce psychosis-like conditions manifested ashyperactivity and increased stereotypic behavior. Known antipsychoticsare able to reverse psychostimulant-induced hyperactivity and increasedstereotypy.

Conditioned avoidance response (CAR) is a behavioral test to evaluateantipsychotic effect of a test compound. It utilizes a shuttle box (MedAssociates, St. Albans, Vt.) with two equal chambers separated by aretractable door. Each chamber is fitted with metal grid floor that iscapable of delivering electric shocks independently. A computer programis used to implement the testing paradigm as well as record the animal'smovement between the two chambers through infrared beam sensors. Thetesting paradigm is as the follows. A mouse is placed into one chamber.A light (conditioned stimulus, CS) comes on. Five seconds later, mildelectric shocks (0.4 mA) (unconditioned stimulus, US) are delivered tothe chamber where the mouse is located (as detected by infrared beams)until the mouse escapes to the adjacent chamber or until 10 sec haselapsed. The US and CS always co-terminate. With randomized inter-trialintervals averaging 15 sec, 30 such CS-US pairing trials are given toeach mouse each day. For each trial, an escape response is registered ifthe mouse crosses to the other chamber after being shocked (i.e., duringthe 10-sec US period), and an avoidance response is registered if themouse crosses to the other chamber during the first 5-sec CS onlyperiod. The animals are trained in such paradigm for 15-20 days, duringwhich the average percentage of avoidance responses will improve to60-80%. This indicates that animals have learned to avoid the onset offootshocks by moving to the opposite chamber upon activation of the CS(light). These trained animals are then used for compound testing usingthe same paradigm. Known antipsychotics have been found to inhibit theconditioned avoidance response, and the ability of new compounds toinhibit this response is thought to be predictive of antipsychoticeffect in humans.

The antipsychotic effect of a test compound may also be evaluated by anovel object recognition test. In a novel object recognition test, miceare housed singly for 1-2 days and then injected with vehicle, PCP, orPCP plus the test compound. Twenty minutes after injection, the mice arepresented with and allowed to explore two identical objects for 30minutes. At the end of the exploration period the objects are removed.Twenty-four hours later each mouse is presented with a pair of objects,one familiar and one novel. After a variable delay, the mice begin toexplore the objects. The time exploring each object is measured for 4minutes starting from the first approach to either object. The fractionof total exploration time spent studying the novel object is recorded asa measure of novelty recognition.

Example 9 Increased Prepulse Inhibition for Compound 5-1

Compound 5-1 (Table 3) was found to increase prepulse inhibition (PPI)similar to olanzapine, as shown in FIG. 1. C57BL/6 male mice wereinjected intraperitoneally (i.p.) with either compound or vehicle.Thirty minutes after injection, the mice were transferred to the PPItesting chamber and evaluated. FIG. 1A shows that olanzapine (3 mg/kg)significantly decreases the startle response (left panel) and increasesPPI at 3 different prepulse levels (right panel) compared to vehiclecontrol (* p<0.05, n=8 per group, student's t-test). FIG. 1B shows thatcompound 5-1 (50 mg/kg) does not affect the startle response (leftpanel) but significantly increases PPI at 3 different prepulse levels(right panel) compared to vehicle control (* p<0.05, ** p<0.01, n=24 pergroup, student's t-test).

Example 10 Reduction of PCP-Induced Hyperactivity for Compound 5-1

Compound 5-1 (Table 3) was found to reduce PCP-induced hyperactivitysimilar to olanzapine and haloperidol, as shown in FIG. 2. C57BL/6 malemice were injected with either compound or vehicle via i.p. Ten minuteslater, the mice were injected with PCP (5 mg/kg) (or vehicle as in FIG.2B) via i.p. The mice were placed in the activity chambers 10 minutesafter PCP injection and their locomotor activities were monitored byinfrared beam breaks for 20 min. FIG. 2A shows that both olanzapine (0.2mg/kg) and haloperidol (0.2 mg/kg) significantly reduce thehyperactivity (left panel) and stereotypy (right panel) induced by PCPas seen in the vehicle+PCP control (p<0.001, n=8 per group, repeatedmeasures ANOVA). FIG. 2B shows that compound 5-1 (50 mg/kg) completelyabolishes the hyperactivity (left panel) and stereotypy (right panel)induced by PCP as seen in the vehicle+PCP control (p<0.001, n=8 pergroup, repeated measures ANOVA).

Example 11 Reduction of Amphetamine-Induced Hyperactivity for Compound5-1

Compound 5-1 (Table 3) was found to reduce amphetamine-inducedhyperactivity similar to olanzapine, as shown in FIG. 3. C57BL/6 malemice were injected with either compound or vehicle via i.p. Ten minuteslater, the mice were injected with amphetamine (2 mg/kg in (FIG. 3A) or5 mg/kg in (FIG. 3B)) via i.p. The mice were placed in the activitychambers 10 minutes after amphetamine injection and their locomotoractivities were monitored by infrared beam breaks for 20 min. FIG. 3Ashows that olanzapine (0.2 mg/kg) partially but significantly reduce thehyperactivity (left panel) and stereotypy (right panel) induced byamphetamine (“amph”) as seen in the vehicle+amph control (p<0.05, n=8per group, repeated measures ANOVA). FIG. 3B shows that compound 5-1 (50mg/kg) also partially but significantly reduce the hyperactivity (leftpanel) and stereotypy (right panel) induced by amphetamine as seen inthe vehicle+amph control (p<0.01, n=8 per group, repeated measuresANOVA).

Example 12 Reduction of Conditioned Avoidance Response for Compound 5-1

Compound 5-1 (Table 3) was found to reduce Conditioned AvoidanceResponse (CAR) similar to haloperidol and olanzapine, as shown in FIG.4. C57BL/6 male mice were trained in the CAR paradigm to predict andavoid the noxious stimulus, reaching a plateau of approximately 20-25avoidance responses per 30 trials (“training plateau”) each day. Themice were then injected with compound or vehicle via i.p., and 20minutes later they were tested for 30 trials in the CAR paradigm.Vehicle treatment and compound treatment were given to the same animalson alternating days, and the effect of compound in reducing avoidanceresponse was analyzed through within-subject comparison (paired t-test).Vehicle exposure (“vehicle”) does not alter the avoidance response ofthese trained animals. FIG. 4A shows that haloperidol (0.15 mg/kg)significantly reduces the number of avoidance response (*** p<0.001, n=6per group, paired t-test). FIG. 4B shows that olanzapine (0.45 mg/kg)significantly reduces the number of avoidance response (** p<0.01, n=6per group, paired t-test). FIG. 4C shows that compound 5-1 (30 mg/kg)significantly reduces the number of avoidance response (*** p<0.001, n=6per group, paired t-test). In all these cases, the numbers of escaperesponse increase correspondingly and the total numbers of transitionsbetween the two chambers do not change (data not shown), indicating aspecific reduction of CAR that is not due to compromised motor function.

Example 13 Reduction of Conditioned Avoidance Response and Hyperactivityfor Compound 5-110

Compound 5-110 (Table 3) was found to exhibit antipsychotic propertiesin two behavioral tests, as shown in FIG. 5. FIG. 5A shows that compound5-110 (10 mg/kg) significantly reduces the number of avoidance responsein the CAR test (** p<0.01, n=6 per group, paired t-test). Experimentalprocedure was the same as in Example 12. FIG. 5B shows that compound5-110 (30 mg/kg) significantly reduces the hyperactivity (left panel)and stereotypy (right panel) induced by PCP (5 mg/kg) (p<0.001, n=8 pergroup, repeated measures ANOVA). Experimental procedure was the same asin Example 10.

Example 14 Reduction of Conditioned Avoidance Response for Compound5-103

Compound 5-103 (Table 3) was found to reduce Conditioned AvoidanceResponse (CAR), as shown in FIG. 6. Compound 5-103 (10 mg/kg)significantly reduces the number of avoidance response (** p<0.01, n=6per group, paired t-test). Experimental procedure was the same as inExample 12.

Example 15 Restoration of Novel Object Recognition for Compound 5-184

Compound 5-184 (Table 3) was found to restore PCP-disrupted novel objectrecognition as shown in FIG. 7. C57BL/6 male mice were injected with 10μL/g of vehicle, PCP (5 mg/kg) or PCP+compound (10 mg/kg) via i.p.Twenty minutes after injection, the mice were presented with and allowedto explore two identical objects for 30 minutes. At the end of theexploration period, the objects were removed. Twenty-four hours later,each mouse was presented with a pair of objects, one familiar and onenovel, and the time exploring each object was measured for 4 minutesstarting from the first approach to either object. FIG. 7 shows that PCP(5 mg/kg) disrupted novel object recognition, that compound 5-184 (10mg/kg) was able to restore novel object recognition performance, andthat olanzapine (1 mg/kg) was unable to restore novel object recognitionperformance (**p<0.01 when compared to PCP-treated group, n=8 per group,ANOVA with post-hoc Bonferroni test).

It will be appreciated that, although specific embodiments of theinvention have been described herein for purposes of illustration,various modifications may be made without departing from the spirit andscope of the invention. Accordingly, the invention is not limited exceptas by the appended claims.

1. A compound having the following structure (IVg):

or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:a is 1, 2, 3 or 4; b is 1 or 2; x is 1, 2 or 3 with the proviso thatwhen x is 1, R¹ is not a single methyl substituent; R¹ represents 1 or 2substitutents independently halogen, C₁₋₆alkyl, —CHF₂ or —CF₃; R² is ateach occurrence the same or different and independently, hydrogen,C₁₋₆alkyl, benzyl, —CH₂CONH₂, —CHF₂, —CF₃, or any two R² groups may betaken together to form a C₁₋₆alkanediyl; R³, R⁴ and R⁵ are the same ordifferent and independently hydrogen or C₁₋₆alkyl; and R⁷ and R⁸ are thesame or different and independently hydrogen, halogen, C₁₋₆alkyl,—O(C₁₋₆alkyl), C₁₋₆haloalkyl or nitro.
 2. The compound of claim 1wherein R³, R⁴ and R⁵ are hydrogen.
 3. The compound of claim 1 whereinR⁷ is hydrogen, R⁸ is —CH₃, a is 1, b is 1 and the compound has thefollowing structure:


4. A pharmaceutical composition comprising a compound of claim 1 and apharmaceutically acceptable carrier or diluent.
 5. A compound having thefollowing structure (IVa):

or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:A is

x is 3 and the —OR² groups are located at the 3, 4 and 5 positions; R¹is absent; R² is at each occurrence the same or different andindependently hydrogen, C₁₋₆alkyl, —C(═O)(C₁₋₆alkyl), benzyl, —CH₂CONH₂,—CHF₂ or —CF₃; and R³, R⁴ and R⁵ are hydrogen.
 6. The compound of claim5 wherein R² is at each occurrence the same or different andindependently C₁₋₆alkyl or —CHF₂ or —CF₃.
 7. A pharmaceuticalcomposition comprising a compound of claim 5 and a pharmaceuticallyacceptable carrier or diluent.
 8. A compound having the followingstructure (IVa):

or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:A is

x is 2 or 3 and two of the —OR² groups are located at the 3 and 4positions; R¹ is absent; R² is at each occurrence the same or differentand independently C₁₋₆alkyl, —CHF₂ or —CF₃; R³, R⁴ and R⁵ are hydrogen;and R⁷ is —O(C₁₋₆alkyl).
 9. A pharmaceutical composition comprising acompound of claim 8 and a pharmaceutically acceptable carrier ordiluent.
 10. A compound having the following structure (IVg):

or a pharmaceutically acceptable salt or stereoisomer thereof, wherein:x is 1, 2 or 3; a is 1; b is 0; R¹ is absent or represents 1, 2, or 3substituents that are the same or different and independently halogen,C₁₋₆alkyl, —CHF₂, —CF₃, —CH₂NH₂, —CH₂NH(C₁₋₆alkyl) or —CH₂N(C₁₋₆alkyl)₂;R² is at each occurrence the same or different and independentlyhydrogen, C₁₋₆alkyl, —C(═O)(C₁₋₆alkyl), benzyl, —CH₂CONH₂, —CHF₂ or—CF₃; R³, R⁴ and R⁵ are hydrogen; and R⁷ is halogen or C₁₋₆haloalkyl.11. The compound of claim 10 wherein R² is at each occurrence the sameor different and independently C₁₋₆alkyl, —CHF₂ or —CF₃.
 12. Thecompound of claim 10 wherein R¹ is absent or represents 1, 2, or 3substituents that are the same or different and independently halogen,C₁₋₆alkyl, —CHF₂ or —CF₃.
 13. A pharmaceutical composition comprising acompound of claim 10 and a pharmaceutically acceptable carrier ordiluent.